Surveying instrument

ABSTRACT

The invention relates to a surveying instrument comprising a telescope, at least one camera providing first, second or more image signals and a controller, wherein the controller is adapted to combine the image signal data of the first, second or more image signals in order to simultaneously display at least two of the images corresponding to the first, second or more image signals on display means.

The invention relates to a surveying instrument and especially to asurveying instrument equipped with at least one camera and a display fordisplaying image information.

In order to aim a surveying instruments' telescope onto a predeterminedtarget point it is known to use an overview image from a camera on adisplay. To verify the correct aiming at the target point, it is knownto magnify a sector of the overview image. These two images can bealternatingly displayed according to an action of a user.

For example, document EP 1 610 092 A1 discloses a surveying instrumentcomprising first and second image pickup units. The second image pickedup has a higher magnification than the first image picked up. When thefirst image is displayed on a display, its magnification can bedigitally changed in a predetermined range. At an upper limit of thepredetermined range effected by switching a zoom changeover switch, thesecond image is displayed. The magnification of the second image can bealso digitally changed.

When changing the zoom range to a large magnification, in cases whereplural points resembling each other exist, it can be cumbersome todetermine whether the magnified section of the image indeed correspondsto the desired section of the overview image and whether the correcttarget point is aimed at. Thus, switching back to the smaller zoom rangemight be necessary in order to accurately determine whether the correcttarget point is aimed at.

Thus, there exists a need for a surveying instrument enabling a fast andaccurate aiming of a telescope by a user.

According to the invention, a surveying instrument comprises atelescope, at least one camera providing first, second or more imagesignals, and a controlling unit for combining signal data. The imagesignals are combined by the controlling unit in order to be displayed asone image on display means at the surveying instrument and/or at aremote controller. The controlling unit is adapted to combine the imagesignal data of a first, second or more image signals to simultaneouslydisplay one, some or all of the images corresponding to the first,second or more image signals on the display means.

In other words, the surveying instrument, in particular theodolite ortotal station, comprises aiming means being swivelable in two directionswith respect to a basis of the surveying instrument and comprising anobjective unit defining an aiming axis and at least a first camerasubstantially in a direction of the aiming axis, wherein the at leastfirst camera provides at least a first image signal. Moreover angle anddistance measurement functionality for determination of the direction ofthe aiming axis and of a distance to a target, display means and acontrolling unit are provided. The controlling unit is adapted so thatthe at least one image signal is processed in order to generate imagesignal data so that at least a first and a second image are displayedsimultaneously, wherein each of the displayed images corresponds to oneof the at least one image signals.

Furthermore, the aiming means comprise an on axis camera as the firstcamera, that is connected to the aiming means, with an opticalmagnification factor providing the first image signal and a wide anglecamera with lower optical magnification factor as a second cameraproviding a second image signal and defining an optical axis.

Further, the surveying instrument is provided with imaging means, aimingmeans that are defining an aiming axis, distance measurement means andangle measurement means. Said means are turnable relatively to a base ofthe surveying instrument and, further, the imaging means comprise an onaxis camera, that is connected to the aiming means, with an opticalmagnification factor and a wide angle camera with lower opticalmagnification factor, wherein a first image signal is provided by the onaxis camera and a second image signal is provided by the wide anglecamera.

Further, the at least one image signals of the on axis camera and thewide angle camera may be processed on side of the surveying instrumentand the images displayed on the display means at the surveyinginstrument as one single image and/or the generated image signal datamay be transferred to the remote controller and the corresponding imagemay be displayed on the display means at the remote controller.Alternatively, the image signals of the on axis camera and the wideangle camera may be transferred in parallel to the remote controller,processed on side of the remote controller so as to generate the imagesignal data and the at least first and second images may be displayed onthe display means at the remote controller.

The main benefit and advantage of this invention is that the user has atleast two video-streams simultaneously on the display whereas each ofthe video-streams contains different information. This informationsupports a fast and accurate aiming process of the telescope onto atarget point by the user. Furthermore, an accurate and reliable targetpoint aiming may need the different video-stream informationsimultaneously in order to clearly determine a unique target point.These can be e.g. video-streams of different wavelength spectrums orATR-video-streams from a camera used for automatic target recognition(ATR), and WAC-video-streams (wide angle camera) without magnification.Thus, the invention provides a solution for the problem to properlyselect a desired target point.

Since the target point might be positioned close to another target pointin a range where the user himself by using his eyes or the WAC (wideangle camera) cannot distinguish the target points anymore, the WAC andfor instance an OAC video-stream (on-axis camera) with magnification oran ATR-camera video-stream are simultaneously available on the displaymeans. Thus, while the WAC video-stream enables an overview of thescenery, while the OAC (or ATR-camera) allows the selection of theproper target point.

In order to explain the invention an example for working with theinstrument is given. A user wants to measure one specific target withina group of targets, wherein the targets are hard to distinguish fromeach other by eye. The user directs a surveying instrument roughly ontothe group of targets. On a display at the surveying instrument and on adisplay at a remote controller that is wirelessly connected to theinstrument a real-time overview image of the environment onto that theinstrument is directed is displayed. Further, a second real-time imagecaptured by a second camera is displayed partly overlapping the overviewimage. The second image comprises a selected e.g. 20-times magnificationof a part of the environment compared to the overview image. By touchingon the overview image on the display the user defines an area thetargets are located at. Afterwards, the instrument is directed to thisarea. The second image now shows this area in the selectedmagnification. Thereon, the targets are clearly separable from eachother. The user now selects the target he is interested in on the secondimage. A mark representing the selected target is shown in the secondand in the overview image and the target is clearly determined. Finally,the user may start a precise measurement of the selected target.

Thus, since the picture on the display consists of more than one imageor image frames, respectively, a user of the surveying instrument canobtain information from all the displayed images at the same time. Forinstance an overview of the measurement scenery in one image frame and adetailed view of the target point in a second image frame can beavailable. Therefore, a fast and accurate determination whether thetelescope is aimed at the correct target point can be made.

Particularly, some or all of the image signals can be at least parts ofdynamic sequences of images or static images. The term image used hereinmay refer to a static image but also to a frame of a dynamic sequence ofimages, in particular a frame of a video stream. These streams can beraw video streams or compressed video streams (e.g. encoded in MPEGformat). Using dynamic sequences, e.g. video streams, enables a realtime judgment of the situation. With other words, the at least firstimage signal may represent a static image or at least parts of dynamicsequences of images, in particular may represent a video streams, inparticular a real time (or substantially real time) video stream.

Furthermore, some or all of the image signals may be provided byseparate cameras. Thus, different images and/or image frames fromdifferent cameras having different optical axes, different optical ordigital zoom factors etc. can be combined in the one picture on thedisplay.

Alternatively, some or even all of the image signals can be provided bythe same camera. Especially when using different digital zoom factorswith the same camera, exact real time magnifications of the sector ortarget point aimed at can be made.

The display means can be located directly at the surveying instrument.Alternatively the display means or additional display means can belocated at a remote controller. Furthermore, additionally oralternatively, the display means can be implemented as an electrooptical viewer in the surveying instrument.

Moreover, the at least first and/or second image may be updated on thedisplay means with a refreshing frequency of 0.1-50 Hz and in particularmay be updated in a continuous manner.

In a further embodiment of the invention, the real time video streamcaptured by an wide angle camera (having a comparatively wide field ofview with no or low optical zoom factor) and the real time video streamcaptured by an on-axis camera being integrated into the surveyinginstruments' telescope having e.g. 30-fold magnification. While the wideangle camera provides an overview image of the whole measurementscenery, the on-axis camera provides a highly magnified image of anaimed sector in order to very precisely align the telescope with thetarget.

Furthermore, particularly, the controlling unit can be adapted toadditionally process and/or combine information from one or morewavelength channels in order to display a combined image on the displaymeans.

Particularly, the images corresponding to the first, second or moreimage signals can be arranged on the display means in an adjacentmanner. Alternatively, or in combination therewith, one or some of theimages corresponding to the first, second or more image signals can bearranged in a manner to partly or fully overlap one or some of the otherimages. Furthermore, the first image corresponding to the first, secondor more image signals is a magnification of a detail of a second imagebeing an overview image. Moreover, an overlapping of the at least firstand second images is generated by displaying at least one of the imagesin the foreground in a semi-transparent manner.

Thereby, particularly, the magnified image can be provided by anothercamera than the overview image. For instance an overview image can beprovided by a wide angle camera, while the magnification of the targetsector can be provided by an on axis camera having a highermagnification. The magnified image can lay over the overview image sothat the centre of the magnified images corresponds to the centre of thedisplay means. The magnified image shows an area of the overview imagecorresponding to the centre of the display means as well.

An offset from the aiming axis to the optical axis may be considered forsimultaneously displaying the first image and the second image.Alternatively, the one image and the overview image can be provided bythe same camera. In this case, the two images are provided by usingdifferent digital zoom factors.

Furthermore, it can be advantageous, if one or some of the images areprovided in defined wavelength channels, in particular colour channels,and/or in adapted modes of representation, e.g. adapted by imageprocessing. One or some of the images can be provided for instance in aninfrared channel or in a night vision mode or in an edge representationmode. Thus, recognition and identification of the correct target pointcan be enhanced and facilitated.

Particularly, the display means can be provided with input means formanually changing the arrangement of the images and for marking and/orselecting points. For instance, the input means can be a touch display,or there can be control buttons, a keyboard or a control stick provided.Furthermore, a combination of one more or all of these input means ispossible.

By use of the input means, for instance, it can be possible to increasethe size of one or some of the images or even to fade out one or some ofthe images. Furthermore, it can be possible to control the presentationon the display means, for example to control the size of the singleimages, the kind of arrangement of the single images, the presentedimages, to choose the sources providing the respective images, tocontrol the sources providing the images, to mark or select parts of theimages and so on.

Furthermore, a user input, in particular a marking and/or a selecting ofpoints or areas, on one of the images is performed, in particularautomatically performed, on at least one adjacent and/or one overlappingimage.

Other advantages and details of the invention will be appreciated fromthe following description of presently preferred embodiments togetherwith the attached drawings. In the drawings:

FIG. 1 a is a schematic view of a surveying instrument according to theinvention positioned in a measurement scenery.

FIG. 1 b is a schematic view of a man-machine-interface (MMI) comprisingdisplay means, which is used with the surveying instrument of FIG. 1 a;

FIG. 2 a is a schematic view of a possible arrangement of images ondisplay means at a surveying instrument or at a remote controlleraccording to an embodiment of the invention;

FIG. 2 b is a schematic view of another possible arrangement of imageson display means of a surveying instrument according to anotherembodiment of the invention;

FIG. 2 c is a schematic view of still another possible arrangement ofimages on display means at a surveying instrument or at a remotecontroller according to an embodiment of the invention;

FIG. 3 is a schematic view of a process changing the arrangement ofimages on display means according to another embodiment of theinvention;

FIG. 4 is a schematic view of an arrangement of two images, one being ameasurement scenery, the other one being an edge presentation of themeasurement scenery in the first image.

The invention will be described on the basis of presently preferredembodiments together with the attached figures. However, the inventionis not limited to the described embodiments, but is merely defined bythe scope of the attached claims.

FIG. 1 a schematically shows a surveying instrument 1 according to theinvention, which is placed in a measurement scenery. Among othercomponents, the surveying instrument 1 includes a wide angle camera(WAC) having a comparatively wide field of view and no or low opticalzoom factor and an on-axis camera (OAC) being integrated into theoptical axis of the telescope of the surveying instrument. Both thesecameras provide a continuous video stream. While the wide angle cameraprovides an overview image 9 of the whole measurement scenery, theon-axis camera provides an image 7 of a sector of the overview image,being in the field of view of the telescope. Therefore, usually, as willbe explained later, the sector image 7 has a substantially highermagnification factor that the overview image. The cameras may bearranged such that their optical axes and/or aiming axes are in paralleland nearly collimate at a target point T in far distance.

Furthermore, the surveying instrument comprises a man-machine-interface(MMI) which among other components has display means 3 as well as akeyboard 5. A not shown controlling unit is used for converting theimage signal data of the WAC and the OAC and for combining the two videostream images 7, 9 in one picture which is displayed on the displaymeans 3, as can be seen from FIG. 1 b. Image 9 is provided by the WACwhile image 7 is provided by the OAC. As can be seen from FIG. 1 b,images 7 and 9 are arranged in an adjacent manner on the display means3.

Via the keyboard 5 it is possible to control the presentation on thedisplay means, for example to control the size of the single images 7,9, the kind of arrangement of the single images 7, 9, control the imagespresented, choose the sources providing the images such as the WAC andthe OAC, control the WAC and the OAC and so on. Additionally, the inputunit can be a touch display. Therefore, some of the above controls canbe effected directly via the touch display instead of using thekeyboard.

For sake of simple presentation, in the following FIGS. 2 a to 4, merelythe display 3 is shown and other components of the MMI are omitted.

FIGS. 2 a to 2 c show different arrangements of images 7, 9 on thedisplay means 3, which are provided by two different cameras which arenamed as camera 1 and camera 2. As can be seen from FIG. 2 a, image 7from camera 1 can be laid over the second image 9 from camera 2 suchthat it is arranged at the position of the target point in image 9.Assuming that camera 1 is the OAC providing a magnified image and camera2 is the WAC providing an overview image of the measurement scenery,this way of presentation enables a direct and real time recognition ofthe correct target point in the proper location of the overview image.Another advantage of this kind of presentation is that the overviewimage has the largest possible size on the display means.

Hence, high precise aiming onto a specific target point is enabled bylooking onto displayed image 7 provided by the OAC, but anyway, at thesame time, the user may also remain an overview of the scenery byconsidering image 9 (of the WAC) being displayed around the OAC-image.Particularly, image 7 may be laid over image 9 in such a way that theaiming axes (optical axes) of both cameras (WAC and OAC) coincide at thesame point on the combined and merged picture being displayed.

FIG. 2 b shows an arrangement of the images 7, 9 where image 7 fromcamera 1 is arranged adjacent to image 9 of camera 2. This alternativekind of presentation can be useful in case it is necessary to maintainthe target point area in the overview image 9, for instance, if there isa plurality of similar objects resembling the target point object closeto each other.

FIG. 2 c shows another possible arrangement of the two images 7, 9 onthe display means 3. Here, image 7 from camera 1 is laid over theoverview image 9 from camera 2, but is arranged in a corner of thelatter. Thus, the full display size is available for the overview imagewhile the sector of the target point is fully visible in the overviewimage 9 as well as in the magnified image 7.

While in the description of FIGS. 2 a to 2 c it was assumed that camera1 is an OAC and camera 2 is a wide angle camera, it is to be noted thatother sources can be used as cameras 1 and 2 instead. For instance oneof the cameras can also be a camera for automatic target recognition(ATR-camera). Such cameras usually are used in order to properly andautomatically align with a reflector. Particularly, the ATR-camera maybe integrated in the telescope and built for detecting in a specificwavelength range (e.g. infrared). Also, both images can be provided fromthe same camera, but one of the image signal data can be modified forinstance by digitally zooming and/or by other image processing methodsand/or by selecting one single colour-channel or an infrared channel.

By pressing directly on the overview image 9 on a touch display, e.g.with a finger, the corresponding area of the overview image is magnifiedin the image 7 as shown in FIGS. 2 a to 2 c.

FIG. 3 shows a schematic view of an operating process in which thepresentation on the display can be changed from the two imagepresentation shown in the upper display means to a one imagepresentation. According to this embodiment, the display means 3 isembodied in the form of a touch display. When touching image 7 providedby camera 1 (OAC) in a defined way, e.g. twice within a short timeperiod (double click), the image is extended to the full size of thedisplay means 3 as can be seen in the lower display. Accordingly, image9 of camera 2 (WAC) is then faded out. By pressing a specified button onthe keyboard 5 or touching the screen in a defined way (e.g., typing ona displayed button or a certain area on the screen), the previousarrangement is restored.

FIG. 4 shows a schematic view of display means 3 presenting two images7, 9. Both images 7, 9 are video stream images and originate from thesame source. They show the same sector of the measurement scenery whileimage 7 was digitally converted to an edge presentation. Asemi-transparent overlapping of both images, for highlighting regions ofinterest, is possible as well.

While some of the presently preferred embodiments of the invention havebeen described in the above, it is to be noted that alternative andadditional modifications to the described embodiments are possible.

While according to the described embodiments, the MMI is provided in theform of a remote control, alternatively the MMI can be provided directlyat the surveying instrument or can be implemented in the surveyinginstrument in the form of an electro optical viewer (EOV), i.e. a microdisplay being visible in the telescope eyepiece.

In the embodiments, the image sources are a wide angle camera and/or anon-axis camera. Additional or alternative sources such as a camera forautomatic target recognition, different wavelength channels of the samevideo stream, different zoom factors of the same video stream may beused to provide additional or alternative image information.Furthermore, the image source may be formed by just one single camera.In this case the image provided by the one camera may be altered bydigitally or optically zooming into a sector of the image, or by otherssuch as the ones described in the following paragraph.

Furthermore, the images presented on the display means may be altered bychanging colour channels or changing the kind of the image presentation,for instance to an edge presentation, an infrared presentation or anight vision presentation. Furthermore, particularly adding additionalinformation such as a reticle, distance information, image counters tothe respective images is also possible.

While in the embodiments described above, video stream images are used,alternatively static images or a combination of both may be used. Usingsimultaneous video stream images enables an actual real timedetermination of the measurement scenery. Alternatively, it is possibleto use a static overview image together with a video stream of an OAC.In this case the overview image is useful for purpose of orientation.

Furthermore, the number of provided images displayed on the displaymeans is not limited to two but can be more than two, depending on therequirements. For instance any of the images 7 or 9 in FIG. 4 can besupplemented by a magnification of a target point sector such that anadditional image is provided or in a manner corresponding to thepresentation of FIG. 2 a.

Furthermore, it may be considered to combine one or more of the videostreams of the cameras at the surveying instrument (WAC, OAC, ATR) withthat of another camera located in a different position (controllercamera). In this case the images from the WAC, OAC and/or ATR as well asthose of the controller camera may be shown on the display means.

Furthermore, it is possible to use more display means. For instance onedisplay may be provided at the surveying instrument while anotherdisplay may be provided on the remote controller. In this case, bothdisplays may show the same picture, or may show different pictures. Forinstance, the display on the surveying instrument may show the videostreams from the WAC and/or the OAC, while the display of the remotecontroller may show the picture of the display on the surveyinginstrument plus additional images.

Furthermore, there can be a possibility that the user individuallyhandles each single image. For instance zooming, exposuring, marking,selecting or colouring might be done via a keyboard or via a touchdisplay or via other control means. Moreover, a change in one image canautomatically and/or manually be transferred to an at least secondimage.

Furthermore, a user input on one of the images can be updated, inparticular automatically updated, in a second or in more images.

Additionally, there can be a possibility to link and change the imagesto foreseen areas on the display means.

Furthermore, several similar or different video-streams (dynamicsequences of images) or images (static images) can be displayed on onedisplay, but each of the video-streams or images can be overlaid withadditional information such as design data, prism information,measurement values, lines, points, areas and/or crosshairs.

Advantages provided by the invention are that, since at least twovideo-streams or static images or a combination thereof can be displayedsimultaneously on display means of a surveying instrument, there is nomore need to switch between video-streams from different cameras or thesame camera but with different zoom factors. A possible offset of theoptical axes of the camera may already be considered for asimultaneously displaying. Therefore, a very fast and accurate aiming ofa target point by the surveying instrument is possible. The overview andthe detail of the scenery are displayed at once. Furthermore, thesimultaneous display of multiple video-streams enables the properselection of the target points, for instance for measurements on prismsor for reflectorless measurements.

1-15. (canceled)
 16. A surveying instrument comprising: aiming meansbeing swivelable in two directions with respect to a basis of thesurveying instrument and including: an objective unit defining an aimingaxis; and at least a first camera substantially in a direction of theaiming axis, wherein the at least first camera provides at least a firstimage signal; angle and distance measurement functionality fordetermination of the direction of the aiming axis and of a distance to atarget; display means; and a controlling unit being adapted so that theat least one image signal is processed in order to generate image signaldata so that at least a first and a second image are displayedsimultaneously, wherein each of the displayed images corresponds to oneof the at least one image signals.
 17. A surveying instrument accordingto claim 16, wherein the surveying instrument is a theodolite or totalstation.
 18. A surveying instrument according to claim 16, wherein theaiming means include an on axis camera as the first camera, that isconnected to the aiming means, with an optical magnification factorproviding the first image signal and a wide angle camera with loweroptical magnification factor as a second camera providing a second imagesignal and defining an optical axis.
 19. A surveying instrumentaccording to claim 16, wherein: the first image from the on axis camerais displayed in the center of the display means laying over the secondimage from the wide angle camera; the first image is a magnification ofan area of the second image corresponding to the center of the displaymeans; and an offset from the aiming axis to the optical axis isconsidered for simultaneously displaying the first image and the secondimage.
 20. A surveying instrument according to claim 16, wherein: the atleast first image signal is processed on side of the surveyinginstrument and the at least first and second images are displayed on thedisplay means at the surveying instrument as one single image and/or thegenerated image signal data is transferred to a remote controller andthe images corresponding to the generated image signal data aredisplayed on display means at the remote controller, or the at leastfirst image signal is transferred in parallel to the remote controller,processed on side of the remote controller so as to generate the imagesignal data and the at least first and second images are displayed onthe display means at the remote controller.
 21. A surveying instrumentaccording to claim 16, wherein the first image corresponding to thefirst image signal is a magnification of a detail of the second imagebeing an overview image.
 22. A surveying instrument according to claim16, wherein the at least first and second images corresponding to the atleast first image signal are arranged on the display means in anadjacent manner.
 23. A surveying instrument according to claim 16,wherein one or some of the at least first and second imagescorresponding to the at least first image signal are arranged in amanner to partly and/or fully overlap one or some of each other.
 24. Asurveying instrument according to claim 16, wherein an overlapping ofthe at least first and second images is generated by displaying at leastone of the images in the foreground in a semi-transparent manner.
 25. Asurveying instrument according to claim 16, wherein some or all of theimage signals are provided by separate cameras.
 26. A surveyinginstrument according to claim 16, wherein at least one of the at leastfirst and second image is provided in defined color-channels and/or inadapted representation modes, in particular adapted by image processing.27. A surveying instrument according to claim 16, wherein the displaymeans are implemented as an electro optical viewer.
 28. A surveyinginstrument according to claim 16, wherein the at least first and/orsecond image is updated on the display means with a refreshing frequencyof 0.1-50 Hz and in particular is updated in a continuous manner.
 29. Asurveying instrument according to claim 28, wherein the at least firstand/or second image is updated in a continuous manner.
 30. A surveyinginstrument according to claim 16, wherein the at least first imagesignal represents a static image or at least parts of dynamic sequencesof images.
 31. A surveying instrument according to claim 16, wherein theat least first image signal represents a video stream.
 32. A surveyinginstrument according to claim 16, wherein the at least first imagesignal represents a real time video stream.
 33. A surveying instrumentaccording to claim 16, wherein: the controlling unit is adapted toprocess information from one or more wavelength channels; and/or thecontrolling unit comprises input means for manually adapting thearrangement of the images and for marking and/or selecting points andareas.
 34. A surveying instrument according to claim 16, wherein a userinput on one of the images is performed on at least one adjacent and/orone overlapping image.
 35. A surveying instrument according to claim 16,wherein a marking and/or selecting points or areas on one of the imagesis automatically performed on at least one adjacent and/or oneoverlapping image.